Use the difference formula for cosecant

In this math example, we first use a reciprocal identity to rewrite the cosecant function as 1/sine. (csc = 1/sin) The difference formula for sine is then used to simplify a trig expression. To do so, we first identify what values will be filled in for each part of the formula (alpha and beta). They are filled in and we simplify by evaluating sine and cosine at the given angle.

csc(pi/2-u)